The present invention generally relates to a fluid or pressure controlling valve and, more particularly, this invention relates to a valve seat apparatus within a fluid or pressure controlling valve.
As is well known throughout industry, including the railroad industry, valves are used in controlling flow and pressure of fluids provided by pumps and compressors. Fluid flows and pressures are conducted through such control valves via pipes, hoses and conduits connected to these valves.
A significant portion of these valves control pressure and flow of fluids by an interaction between the sealing surface of a moveable valve apparatus and a corresponding valve seat, each of which come together or separate to control the flow of a fluid from an inlet portion of a valve to an outlet portion of a valve.
Some of these interacting valve members involve a rigid carrier of metallic, or similarly suitable material, that provides a surface to attach an elastomer sealing member. The sealing member of rubber, or a similar elastomer, generally is bonded to the metallic carrier to provide a substantially flexible cushion that would conform to the surface of the corresponding sealing seat and create an effective seal.
The carrier, to which the sealing member is attached, is carried by rod or stem connected to a diaphragm or a solenoid to which the sealing member is forced against the corresponding sealing seat to create an effective seal against the flow or pressure of the fluid to be controlled. Consequently, the same carrier and sealing member retracts away from the corresponding sealing seat to effectively open the seal and permit the flow of the fluid being controlled. This compression and decompression of the sealing member, as well as repeated separations from the corresponding sealing seat contributes to accelerated delamination of the sealing member from the carrier. This separation of the sealing member from the carrier eventually may render the valve useless for controlling fluid flow or pressure.
It is generally required that fine machining and polishing of the surface of the metallic carrier be performed to improve attachment of the sealing member. Such machining and polishing of the carrier and the attachment of the sealing member to the carrier may substantially increase production cost of the component. In addition, a bonding agent compatible with both the carrier and the elastomer sealing member is indispensable. Errors in production or assembly of the sealing apparatus could contribute to loss of operation and failure.
As opposed to the prior art valve seat apparatus that is a combination of two separate components, the present invention provides a valve seat apparatus that provides both a sealing surface and carrier portion engageable with a stem assembly within a valve housing. Interaction between the valve seat apparatus and a corresponding sealing member within the valve housing control the flow of fluid and fluid pressure. The valve seat apparatus is comprised of a preselected plastic material that possesses at least sufficient mechanical rigidity for stable attachment to a stem assembly and transmission of an actuating force as well as provide a sealing surface with enough resilience to mate with the corresponding sealing member and establish an effective seal.
According to a second aspect, the present invention provides, in combination with a valve having a valve housing, a diaphragm and stem attached with a sealing surface disposed thereon, the improvement comprising a valve seat apparatus that combines a sealing surface and a carrier portion. Interaction between the valve seat apparatus and a corresponding sealing member within the valve housing control the flow of fluid and fluid pressure. The valve seat apparatus includes a preselected plastic material of sufficient mechanical rigidity to transmit an actuating force and allow stable attachment to a stem assembly yet is sufficiently resilient to facilitate a seal with the corresponding sealing member within the valve housing.
It is, therefore, a primary objective of this invention to provide a valve seat apparatus in which a carrier and sealing surface are constructed of one contiguous material for use in a valve that controls fluid or fluid pressure.
Another objective of the present invention is to provide a valve seat apparatus which utilizes a material that possesses enough of an elastic and conforming nature that it can provide a sealing surface yet sustain sufficient mechanical rigidity to transmit an actuating force and permit stable connection to required components.
Yet another objective of this invention is to provide a valve seat apparatus that is relatively simple to form and manufacture.
A further objective of this invention is to provide a valve seat apparatus that is comparatively inexpensive to produce.
An even further objective of this invention is to provide a valve seat apparatus which will enable production of a fluid-controlling valve that is potentially more reliable.
A yet further objective of this invention is to provide a valve seat apparatus which eliminates the need to bond a separate elastomer sealing member to a rigid carrier to create such valve seat apparatus.
In addition to the objectives and advantages listed above, various other objectives and advantages of the present invention will become more readily apparent to persons skilled in the relevant art from a reading of the detailed description section of this document. The other objectives and advantages will become particularly apparent when the detailed description is considered along with the attached drawings and the appended claims.